We seek funds to extend our studies on human monoclonal HIV-1 antibodies to include a wider spectrum of such antibodies, to determine their molecular architecture, and from assay systems to select those with the most likely possibility of providing viral neutralization in vivo. Molecular genetic approaches are proposed to develop higher affinity human antibodies that could be used potentially for both prevention and treatment of human infection with HIV-1. Collaborations have been established to determine HIV specificities of the reagents in vitro and their potential use in nonhuman primate models in vivo.